Portable power supply



FIG. 1 is a top, front, right side perspective view of a portable power supply showing our new design;

FIG. 2 is a front elevation thereof;

FIG. 3 is a rear elevation thereof;

FIG. 4 is a right side elevation thereof with the left side being a mirror image;

FIG. 5 is a top plan view thereof; and,

FIG. 6 is a bottom plan view thereof.

The broken lines present in the figures are included for the purpose of illustrating portions of the portable power supply which form no part of the claimed design. 

CLAIM The ornamental design for a portable power supply, as shown and described. 